Expansible piston



Dec. 13, 1932. c. s. JOHNSTON EXPANSIBLE RISTON- 2 Sheets-Sheet 1 Original :Filed Nov. 28, 1930 l l-iihl. IIIIIIII Ir-III II I II I I Ill-IL C. S .I'Jbhnsfon 351% A Home y Dec. 13, 1932.

I c. s. JOHNSTON EXPANSIBLE PI S TQN Original Filed Nov. 28, 1950; 2 Sheets-Sheet 2 Inventor 0.1 .tfohnszon A llomey Patented Dec. 13, 1932 PATENT entries,

CLARENCE S. JOHNSTON, OF AMARILLO, TEXAS- EXPANSIBLE. PISTON 7 Application filed November 28, 1930, Serial no, 498,800. Renewed'April'm, 1932.

This invention relates to certain new and useful improvements in pistons and the primary object of this invention is to provide an expansible piston that may be readily and manually expanded for compensating for wear on the periphery of the piston.

The primary object of this invention is to provide a piston formed of one piece, that is to say a piston, the head and skirt of which are integral, together with means incorporated with the piston to facilitate expanding the piston.

A still further object of the invention is to provide an expanding piston, that may be uniformly expanded, so as to insure uniform diameters throughout the length of the piston when the latter is expanded, and further, to provide such an expanding piston, that will be strong, durable, and which will be thoroughly practical and efiicient in operation.

Other objects and advantagesof the invention will become apparent during a study of the following description, taken in connection with the accompanying drawings where- Figure 1 is an elevational view of the piston.

Figure 2 is a bottom plan View thereof.

Figure 3 is a vertical transverse sectional view taken substantially on the line 33 of Figure 2.

Figure 4 is a fragmentary vertical sectional view taken substantially on the line 4-4 of Figure 3.

With reference more in detail to the drawings, it will be seen that the ex anding piston is formed of one piece, anc of suitable material and includes a head 5 and a skirt 6, the piston in its entirety being hollow, and the head provided with the usual grooves for receiving the piston rings'7.

In carrying out my invention, the piston is split circumferentially at the junction of the head 5 and skirt 6 as at 7.

On diametrically opposite sides thereof the the skirt and extending across the opening i 8 isa boss9' which boss 9,- adj acentits longitudinal edges is provided with slots-10 forming connecting webs llth'at are integral with thewall of the skirt 'adjacent the side edges of the opening 8. Intersecting'each slot 10 is-ayertical' bore- 12 that tapers longitudinally and has its smaller end at the upper skirt to theJ-lower end ofthe opening 8;

F-rom the=foregoi-ng it 1 willbe' seen that by threading the screws 13 upwardly of the respective bores 12, the slots 10will be expanded, resulting inan expansion of the en'- tire cylinder throughout" its-length, with :the result? that when;expanded, the piston will maintain the:uniform diameter throughout its entire length.

Each boss 9 at its upper end merges into an integral connecting web 15 risingfrom the boss, which'web:151isalso integral with the head5 as shown to advantage inFi'gures 1', 3and4;

Gn itsinner face, each of the bosses-'9 is recessed as at 16, and opposite the recess, the bossis provided with a suitable aperture 17 that is counterbored "as at 18 for accommodatingoneendlof asuitable wrist pinshown inrFi 'ure-t-and designated generally by the reference character19. I

From theforegoingit will be apparent that theboss, having-web 15' integral there with, and integral with the head 5, and in turn being integral with the skirt-'6' through themedium of the connecting portions or webs 11, that thehead-5 and-skirt Gware sub stantially integral one with the other, and incapable of axialmovement relative to. one another.

The piston-.beingsplit, at7, and on;dia+

metrically opposite sides of the skirt as at in relatively opposite directions to thereby 14, together with the provision of the diaradially expand said skirt.

metrically opposed openings 8 will permit of expansion of the piston without distorting the latter.

From the foregoing then it will be seen that I have devised a piston, that may be readily and easily expanded, and which when expanded, will maintain uniform diameter throughout its length.

Even though I have herein shown and described the preferred embodiment of the in- In testimony whereof I afiix my signature.

vention, it is to be understood that the same i is susceptible of changes, modifications and arrangements coming within the scope of the appended claims.

Having thus described my invention, what I claim as new is: 1 V

1. An expansible piston including in combination a skirt provided on diametrically opposite sides with an opening, a boss integral with the skirt at opposite sides of each opening, each of said bosses provided with slots opening inwardly from one face thereof and means for expanding the slots for effecting expansion of the piston.

2. An expansion piston including in combination a skirt provided on diametrically opposite sides thereof with openings, a boss opposite each of said openings and integral with the skirt adjacent opposite sidesof the respective openings, each of'said bosses adjacent opposite vertical edges provided with a slotopening inwardly from one face of the boss and expanding means engageable with each slot.

3. An expansible piston including a skirt apertured at opposite sides thereof, a boss adjacent each aperture, connecting webs integral with the boss and skirt at opposite sides of the aperture, and wedge means between said webs and adjacent portions of the boss for effecting an expansion of the piston.

4L An expansible piston including in combination a head and a skirt, said piston being split circumferentially at the junction of said head and skirt, oppositely disposed. bosses arranged in the piston for supporting a wrist pin, each of said bosses provided with a web united with said head, together with op positely disposed webs united with said skirt, whereby provision is made for retaining the head and skirt against axial movementrelative to one another, and means interposed between the bosses and thewebs united with said skirt for effecting radial expansion of the skirt.

5. A piston including a radially expansible skirt, and means for expanding said skirt, said means including a member provided with webs united with said skirt in spaced relation with respect to one another, and means interposed between said webs and said member for effecting a movement of the webs CLARENCE S. JOHNSTON. 

